This invention relates to fiber optic termination assemblies and a method for arranging and positioning optical fibers.
Fiber optic assemblies containing multiple optical fibers (i.e. a fiber optic bundle) are often used for light transmission in various applications for telecommunication and instrumentation in which light is collected at an emitter and transmitted to a receiver. Various designs for fiber optic termination assemblies for containing and positioning these fibers bundles have been proposed in the prior art, the main design consideration being optimal coupling in and out of the fiber optic bundle. The termination apertures used to arrange and position the fiber optic bundle may take various forms including round, square, rectangular, linear, and so on. Individual optical fibers within the bundles are generally loose except at the termination where they are arranged in a tightly packed structure (typically a hexagonal arrangement) in order to maximize light transmission efficiency. As the optical fibers may be very fine, the tolerances required to ensure proper positioning of the fiber bundles at the termination may be very high. With existing fiber optic termination assembly designs, achieving the high tolerances necessary for proper arrangement and positioning of the fiber bundles has been difficult. It is particularly challenging when fibers have to be arranged in a single tightly packed line as required, for example, in telecommunications applications involving wavelength multiplexing.
Thus, there is a need for a design for a fiber optic termination assembly which facilitates accurate arrangement and placement of the fiber optic bundles, and which is inexpensive to manufacture and assemble.
It is an object of the present invention to provide an improved fiber optic termination assembly which facilitates arrangement and positioning of optical fibers.
In a first aspect of the present invention, there is provided a fiber optic termination assembly for arranging and positioning a fiber optic bundle, comprising:
(i) a pair of aperture-forming elements adapted to abut each other in a reciprocal fashion to form at least one aperture to contain said fiber optic bundle; and
(ii) a sleeve adapted to receive said pair of aperture-forming elements;
whereby, the reciprocal arrangement of said pair of aperture-forming elements results in a desired positioning of said fiber optic bundle within said fiber optic termination assembly.
In one embodiment, each of said aperture-forming elements has an outer surface, at least first and second abutting surfaces, and at least a third opposing surface provided between said first and second abutting surfaces, the first and second abutting surfaces of one of said elements being reciprocally arranged to abut the second and first abutting surfaces respectively of the other of said elements.
In another embodiment, a protruding ridge is provided on at least one of said first and second abutting surfaces, and a corresponding recessed groove is provided on the other of said first and second abutting surfaces, whereby, in use, said protruding ridge and said recessed groove lock to determine the size of the aperture formed between said elements.
In yet another embodiment, a portion of the outer surface of each aperture-forming elements, on which a force may be applied opposite to a force which may be applied by the opposing surface, is recessed relative to an adjoining outer surface, so that, in use, said sleeve does not act to widen said aperture.
In another aspect, the present invention provides elements for a fiber optic termination assembly for arranging and positioning a fiber optic bundle, comprising:
(i) a pair of aperture-forming elements, each of said elements providing an outer surface, at least first and second abutting surfaces, and at least a third opposing surface provided between said first and second abutting surfaces;
(ii) wherein, said pair of aperture-forming elements are adapted to abut each other in a reciprocal fashion to form an aperture for arranging and positioning said fiber optic bundle.
In one embodiment, a protruding ridge is provided on at least one of said first and second abutting surfaces, and a corresponding recessed groove is provided on the other of said first and second abutting surfaces, whereby, in use, said protruding ridge and said recessed groove lock to determine the size of the aperture formed between said elements.
In another aspect, the present invention provides a method of assembling a fiber optic termination assembly for arranging and positioning a fiber optic bundle, comprising the steps of:
(a) providing a pair of aperture-forming elements, each of said elements providing an outer surface, at least first and second abutting surfaces, and at least a third opposing surface, and arranging said elements in a reciprocal fashion about said fiber optic bundle;
(b) arranging and positioning said fiber optic bundle between said abutting and opposing surfaces; and
(c) bringing said aperture-forming elements together to secure said fiber optic bundle within an aperture formed between said elements.
In one embodiment, the method further comprises the step of preparing said optical fibers prior to bundling by cleaning and buffer-stripping said fibers.
In another embodiment, the method further comprises the step of inserting said pair of aperture-forming elements within a sleeve to secure said elements together.
In yet another embodiment, the method further comprising the step of securing said elements together using an adhesive.
An advantage of the present invention is that, by providing a pair of like aperture-forming elements which are arranged in a reciprocal fashion, proper positioning (i.e. centering) of the fiber optic bundle at the termination is ensured. Also, since the like aperture-forming elements can be manufactured simultaneously with the same mold or die, tight tolerances for the fiber optic bundle containing aperture can be achieved.
Another advantage provided by the present invention is that, due to the tight tolerances that can be achieved, very small apertures can be formed to precisely position even a few strands of optical fibers.
A further advantage is the mechanically simple fabrication method. The solution taught by the present invention is particularly advantageous when a single line of fibers is needed, which may have applications in spectroscopy, telecommunications, and laser beam multiplexing.